A common household annoyance and danger occurs when a kitchen range burner is operated without a utensil being present thereon. This may occur when the control knob is left in a burner-on condition after the utensil has been removed. Alternatively, the operator may activate the burner intending to utilize it, only to be interrupted in his kitchen task and forget that the unemployed burner remains on.
This problem can easily avoid the operator's attention, especially at very low heat levels (e.g., when the burner control knob is in a low-heat position), where it is often impossible to visibly detect that the burner is operating. An electric burner may not glow, and the gas flame is reduced in size at such low heat levels.
Operating a burner without the utensil present wastes energy. It also creates a safety hazard which may result in serious burns for the unwary operator, especially when the burner is on the low setting where the operator may not notice that the burner is hot.
Conventional devices do not adequately solve this problem. One device depicts an alarm device which indicates that less than a desired weight is on the burner. However, that device is basically a measuring mechanism and does not operate to indicate that the stove burner is turned on: the alarm functions completely independently of the stove burner and its control knob. Another device uses an electric heating element which is activated when a utensil is placed upon it. However, such a device must be wired as part of the burner and is not designed to be installed in existing burners. Further, this device functions only with electric, and not with gas, burners.